1. Field of the Invention
The present invention relates to a connector checker for detecting an incomplete insertion state of a terminal inserted in a connector, particularly to a connector checker having a main body in which a detection pin can be inserted without an undesirable looseness to prevent damage of the detection pin.
2. Related Art
Referring to FIGS. 3 to 5, a known connector checker will be discussed hereinafter. FIG. 3 is a perspective view of a known connector checker. FIGS. 4A and 4B each are a sectional view showing an operation step of the connector the checker, and FIGS. 5A and 5B each are an enlarged view of FIG. 4A or 4B.
In FIG. 3, reference numeral 100 designates the connector checker having a base structure 10 provided with two guide shafts 50, 50. On the base structure, there are disposed a holder 20 and a checker main body 300 which are slidable along the guide shafts 50, 50.
The holder 20 is a frame holding a housing 81 of a connector 80 inspected therein, and each guide shaft 50 has a spring 60 mounted around it for resiliently urging the holder 20 toward the checker main body 300.
As illustrated in FIG. 3 and FIG. 4A, the checker main body 300 has an engagement recess 301 engageable with a forward portion of the housing 81 of the connector 80 and has a plurality of through holes 302 each associated with one of terminal accommodation chambers 82 of the connector 80.
As illustrated in FIG. 5A, each through hole 302 of the checker main body 300 accommodates a detection pin 40. Each detection pin 40 has a continuity sensing portion 40a and an incomplete insertion detection portion 40b in a forward side thereof. The detection pin 40 is resiliently biased by a spring 41 toward the holder 20.
The thus configured checker main body 300, as illustrated in FIGS. 4A and 4B, can be moved forward and backward by an actuation lever 70.
As illustrated in FIG. 3 and FIG. 5A, The connector 80 has the housing 81 formed with a plurality of the terminal accommodation chambers 82. Each terminal accommodation chamber 82 has a resilient locking arm 83 integrally formed therein.
The terminal accommodation chamber 82 receives a terminal 84 so that the locking arm 83 engages with a slit 84a formed in the terminal 84 to hold the terminal 84 within the terminal accommodation chamber 82.
Note that, when the terminal accommodation chamber 82 has incompletely received the terminal 84, that is, when the terminal 84 has been incompletely inserted therein, the locking arm 83 does not engages with the slit 84a of the terminal 84 as illustrated in FIG. 5B.
In the mean time, electrical wires 42, 85 (see FIG. 3) connected to the detection pin 40 or the terminal 84 are electrically connected to an electrical continuity checking apparatus (not shown). Thus, an operator uses the checking apparatus for detecting an incomplete insertion state or an incorrect continuity state of the terminal 84.
Next, referring to FIGS. 4A, 4B and FIGS. 5A, 5B, checking operations of the connector checker 100 will be discussed.
In FIGS. 4A and 5B, the holder 20 of the connector checker 100 receives the connector 80 to beset thereon, and pivoting the actuating lever 70 moves the checker main body 300 toward the connector 80.
Accordingly, as illustrated in FIG. 4B and FIG. 5B, the engagement portion 301 of the checker main body 300 engages with a forward portion of the connector 80, and each terminal accommodation chamber 82 of the connector 80 receives the associated detection pin 40.
In this state, when the terminal accommodation chamber 82 has completely received the terminal 84, the incomplete insertion detection portion 40b of the detection pin 40 has advanced under the locking arm 83. Thus, the continuity sensing portion 40a of the detection pin 40 contacts the terminal 84, so that the checking apparatus indicates a correct continuity state of the connector, for example by turning on a lamp.
Meanwhile, when the terminal accommodation chamber 82 has incompletely received the terminal 84, the incomplete insertion detection portion 40b of the detection pin 40 abuts against the locking arm 83, preventing the continuity sensing portion 40a of the detection pin 40 from contacting the terminal 84. Thus, the checking apparatus indicates an incorrect continuity state of the connector, for example by not turning on a lamp.
The known connector checker 100, as illustrated in FIG. 6, has the detection pin 40 which is rectangular in section, while the through hole 302 of the checker main body 300 is an elongated one slightly larger than the rectangular section of the detection pin 40. The elongated through hole 302 has an arc portion which allows looseness of the detection pin 40 within the through hole 302. Thus, at an engagement operation of the checker main body 300 with the connector 80, the detection pin 40 may abut an end wall of the housing 81, disadvantageously causing damage of the pin 40 or the end wall of the housing 81.
This problem may be eliminated by providing another through hole 302 of the checker main body 300 which has a rectangular section similar to the detection pin 40.
However, since the through hole 302 of the checker main body 300 is machined generally by a rotating cutter of an end mill, it is difficult to form the rectangular through hole 302 by using such a tool.
Furthermore, a plurality of the through holes 302 is machined to be formed one after another in the checker main body 300, so that the mutual distances of through holes 302 are not sufficient in precision, causing abutment of the detection pin 40 against the housing 81.
In view of the above-mentioned disadvantages, an object of the present invention is to provide a connector checker that can eliminate looseness of a detection pin within the checker main body. The checker allows an improved precise positioning of the detection pin, surely preventing damage of the detection pin.
For achieving the object, a connector checker according to the invention has a main body with a block accommodating a plurality of detection pins movable forward and backward in the block each for detecting an incorrect insertion state of a terminal which is inserted in a terminal accommodation chamber of a connector by inserting the detection pin into the terminal accommodation chamber. The checker main body has a plurality of through holes vertically elongated in section and a plurality of through holes horizontally elongated in section. The vertically elongated through holes are disposed to partially overlap with the horizontally elongated through holes to define a plurality of rectangular openings. Through one of the rectangular openings, the detection pin is inserted so as to adequately limit vertical and horizontal movements of the detection pin within the terminal accommodation chamber.
The thus configured checker has the vertically elongated holes disposed perpendicular to the horizontally elongated holes. Even when each elongated hole has each end of an arc shape, the plurality of rectangular openings can be defined each as corresponding to a sectional shape of the detection pin.
The detection pin is inserted through the rectangular opening, so that the vertical and horizontal movements of the detection pin is adequately limited to eliminate the undesirable looseness of the pin within the rectangular opening. This prevents the detection pin from abutting against the connector housing, causing no damage of the pin.
The method of defining a plurality of the rectangular openings by disposing the vertically elongated holes perpendicular to the horizontally elongated holes allows a greatly improved precise positioning of the rectangular openings than a known method in which through holes for detection pins are formed one after another. The improved method prevents damage of the pins during insertion thereof.
Preferably, the block of the checker main body is formed with the vertically elongated through holes or the horizontally elongated through holes, while a plate is formed with the horizontally elongated through holes or the vertically elongated through holes to define the rectangular openings. The vertically elongated through holes are parallel with each other, and the horizontally elongated through holes are parallel with each other. The plate is mounted on a surface of the block which has open ends of the elongated holes.
In the thus configure checker, the block or the plate may be replaced by another block or plate which has a different number of elongated holes, allowing to efficiently inspect various types of connectors having a different number of terminals.
Preferably, the elongated holes of the block may be separated from each other by partition walls, while the elongated holes of the plate are also separated by partition walls. The elongated holes of the block are disposed to abut against and perpendicular to the elongated holes of the plate to define the plurality of the rectangular openings.
In the thus configured checker, the rectangular opening is defined by four partition walls of the vertically elongated holes and the horizontally elongated holes, allowing a stable support of the detection pin.